Expansion bolt



May 23, 1939. M. F. \ZIFFERER EXPANSION BOLT Filed Aug. 30, 1937 Patented May 23, 1939 EXPANSION sour Morton F. Ziflerer, Great Neck, N. Y., assignor, by mesne assignments, to U. 8. Expansion Bolt 00., York, Pa., a corporation of Pennsylvania Application August 30, 1937, Serial No. 161,600

3 Claims.

This invention relates to improvements in expansion bolts of the type comprising an expansible shield and a tapered nut or expander. One of the objects is to provide a locking means slots of the shield, and formed adjacent the base of each rib on opposite sides thereof is a groove IS. A beveled recess ll which extends transversely across each side of the nut provides in 5 whereby the proper assembly of the shield and eilect a ratchet shoulder between each two ribs 5 nut is assured, and whereby an initial expansion thereof which is adapted to receive engagement I is readily obtainable. Another and equally imfrom the shield hook to hold the nut in a posiportant object is to provide means whereby the tion of partial or complete insertion within the expansive strains are withstood by the nut and shield, as shown, respectively in Figs. 2 and 3.

shield in an improved manner. In advancing from one position to the other 10 These and other objects of the invention will each hook rides up and along the engaged side be described in the following specification whereof the nut so that in the position of complete inin reference is made to the accompanying drawsertion expansion of the shield sections has aling which illustrates an embodiment thereof in ready started. The nut is retained in assembled the manner following: relation with the shield in either of these two 15 Figure 1 is an elevation view of the expansion positions. The nut can thus be locked within device complete with bolt, showing the nut parthe-shield with capacity to move only inwardly. tially inserted within the shield at the inner end; By advancing the nut the shield will be initially Fig. 2 is a central longitudinal section thereexpanded to insure a tight anchorage, thus overof; coming any tendency of rotation on the part of 20 Fig. 3 which is a longitudinal section shows e Shield d g t e e y Stages of the p the nut advanced completely within the shield ing operation. to produce an initial expansion thereof; The nut transmits expanding forces to the shield Fig. 4 is a longitudinal section showing the nut at eig t different P two points adjacent each further advanced to cause an increased expancorner close to one of its ribs. This is important 25 sion of the shield, a lag bolt being indicated in because the nut is of its maximum thickness at co-operation therewith; these points where it is possessed of adequate Fig. 5 is an enlarged cross-section through strength to resist crushing. The nut is prevented the device taken on line 55 of Fig. 2 looking from turning by the ribs l5 which protrude into in the *direction of the arrows; the shield slots ID. The bore within the nut may 30 Fig. 6 is a similar view taken on line 6-6 of be provided with threads for co-operation with Fig. 4; and .any standard form of bolt, a lag bolt being illus- Fig. 7 is a perspective view of the nut per se.,' trated by way of example.

The device herein shown comprises a one- Iclaim:

piece shield S and an expanding nut N adapted 1. In an expansion bolt the combination of a 35 to be operated by a bolt B. The shield is formed one-piece shield having a plurality of slots extendwith a. plurality of slots l0 each extending loning longitudinally from its inner end for a major gitudinally from its inner end for a major porportion of its length to provide'a like number of tion of its length to provide a like number of sections each outwardly yieldable to engage with 4 Sections ll eac outwardly y b e to engage the walls of a surrounding aperture, the shield 40 with the walls of a surroundingaperture. Exbeing formed with an axial passageway which is tending axially through the Shield is a p ssa e transversely arcuate throughout its several secy Which is transversely fl e throughout tions each of which is outwardly tapered in the its several sections. The inner face of each secregion oi its inner end, a nut having a plurality of tion s ou w y tapered as at in the region sides corresponding in number and generally in 45 of its inner end. At the inner end of the shield taper to the sections or the shield, a rib extending is an ar y protruding k 3 in the form longitudinally along each corner of the nut of a lus well, one or more of them, adapted adapted to slide within one or the longitudinal to engage the nut in a manner which will now slots of the shield, there being a pair of grooves be explained. adjacent the base of each rib and a recess extend- 50 The nut is formed with a plurality of sides ing transversely of one side of the nut and beveled corresponding in number and generally in taper inwardly toward its outer end to provide in effect to the sectio s of the Shield- Extending l nsia ratchet shoulder between two ribs thereof, and tudinally along each corner of the nut is a rib a hook extending inwardly from the inner end of I5 adapted to slide within one of the longitudinal the shield adapted to engage the nut either at the 55 inner end or the shoulder thereof whereby to retain the nut in assembled relation within the shield in either of two positions, the nut being free to advance from its outer to an inner position but not vice versa.

2. In an expansion bolt the combination of a one-piece'shield having a plurality of slots extending longitudinally from its inner end for a major portion of its length to provide a like number of sections each outwardly yieldable to engage with the walls of a surrounding aperture, the shield being formed with an axial passageway which is transversely arcuate throughout its several sections each of which is outwardly tapered in the region of its inner end, a nut having a plurality of sides corresponding in number and generally in taper to the sections of the shield, there being a recess extending transversely of each side of the nut and beveled inwardly toward its outer end to provide in effect a ratchet shoulder, and a hook extending inwardly from the inner end of the shield adapted to engage the nut either at the inner end or the shoulder thereof whereby to retain the nut in assembled relation within the shield in either oftwo positions, the nut being free to advance from its outer to an inner position but not vice versa.

3. In an expansion bolt the combination of a one-piece shield having a continuous circular head, a plurality of slots proceeding longitudinally from its inner end through a major portion of the shield length to provide a like number of spring sections each outwardly yieldable under tension to engage with the walls of a surrounding aperture, the shield being formed with an axial passageway of substantially uniform cross sectional area from the head end to a point relatively close to the inner end of the shield, the passageway being transversely arcuate through its several sections and eachof said sections being outwardly tapered in the region of its inner end, a polygonal nut having a plurality of sides corresponding in number and generally in taper to the sections of the shield and a rib extending longitudinally along each corner of the nut adapted to slide within one of the longitudinal slots of the shield, there being a pair of grooves adjacent the base of each rib adapted to receive engagement from the proximate comer of the shield section whereby to confine the transmission of expansive forces radially through such points, and the nut fitting snugly within the inner end of the shield prior to expansion thereof in a manner whereby to exert an outward thrust upon each of the shield sections proceeding from points adjacent the base of each rib on the nut to the proximate corner of the adjacent shield section.

MORTON 'F. ZIF'FERER. 

